7    Window System Software Notes

This chapter contains notes about issues and known problems with the windowing software and, whenever possible, provides solutions or workarounds to those problems. The following topics are discussed in this chapter:

7.1    Hardware Notes and Restrictions

The following notes apply to graphics hardware restrictions.

7.1.1    PowerStorm Graphics Support

Support for the following 3D graphics adapter families is included on the Associated Products CD-ROM:

The base operating system provides only VGA mode support for these devices. Drivers for these devices are available at the following URL:

http://www.support.compaq.com/open3d/

7.1.2    Qvision Graphics Display Error

Different versions of Qvision graphics boards demonstrate fillsolid drawing problems, leaving a line at the bottom of the screen, which is evident when you run the CDE blank lock screen. The line varies in color and intensity depending on the version of the Qvision board.

7.2    X Servers

The following notes apply to X servers.

7.2.1    Limited Multiscreen Display Support with CDE

CDE provides limited support for X servers with more than one screen. While a multiscreen environment is possible, a number of inconsistencies are noticeable. For example, colors in secondary screens may not be correct, icons may not display properly, and applications may not appear on the screen where they are invoked. Using the PanoramiX extension mitigates some of these inconsistencies.

7.2.2    Pixmap Color Errors with PanoramiX

Some pixmap color corruption has been seen when using the PanoramiX extension. Background pixmaps can be corrupted when a client is displayed on any screen other than the physical screen 0. The corruption is most frequently seen when using Netscape and loading pages with background pixmaps.

To avoid this problem, check the "Always use my colors, overriding document." box under the color section of Netscape preferences.

7.2.3    X Print Server Extension Library Restriction

Programmers who may be using the X Print extension library in combination with the X Print Server shipped as a subset of the base operating system should be aware that the library calls XpCancelDoc() and XpCancelPage() are currently not functional. Their use triggers no operation to be performed.

7.3    CDE Clients

The following notes apply to CDE clients.

7.3.1    Inaccessible Dialog Buttons

When you use low resolution graphics, the buttons in a dialog box, such as OK, Apply, Cancel, and Help, might not display. For CDE and Motif based applications, set the DXmfitToScreenPolicy resource to as_needed in the application's resource file under your home directory or, to make it effective systemwide, in the /usr/dt/config/$LANG/sys.resources file.

For non-Motif based SysMan applications, such as those launched from SysMan Menu, see Section 5.2.9.

7.3.2    Remote Invocation of CDE File Manager dtfile

File Manager, Application Manager, and Trash Manager are different views supported by the dtfile application. Avoid invoking dtfile from a remote system with the DISPLAY environment variable set appropriately. This restriction is necessary because of the client-server model used by the dtfile application and its close interaction with the ToolTalk messaging system.

In the event of unexpected behavior from any of these utilities, close all windows associated with the File Manager, Application Manager, and Trash Manager. Then kill all processes associated with the dtfile application. You can obtain the pid for each process by using the following command: 

# ps -aef | grep dtfile

7.3.3    Possible Failure in the XOpenDisplay Call

When a user logs in to the CDE desktop, some applications might not restart. The X server process might not be able to handle all of the requests for new open connections, causing some to fail in the XOpenDisplay call. Some applications, like xterm, log startup errors such as the following in the dxconsole window: 

xterm error: can't open display :0

To avoid this problem, add the following resource to your $HOME/.Xdefaults file: 

Dtsession*contManagement:   2

This resource enables a handshake protocol between the CDE Session Manager and Window Manager during the login phase to control the appearance of new windows. While it might marginally increase the time before the login completes, it better assures that all applications will restart.

You can add the resource to the /usr/dt/app-defaults/C/Dtsession file to make the change for all users automatically.

7.3.4    Login to CDE_SESSION Restriction

Login to CDE_SESSION is restricted to machines with host names that are not greater than 31 characters. This is because CDE and the X libraries use the uname command to get the system name to process the user credentials.

7.3.5    Possible Problem with CDE ToolTalk Messaging

The $HOME/.TTauthority file contains a key that ToolTalk clients read and send to the ttsession message server along with each message. The ttsession message server compares this key with the key it placed in the user's $HOME/.TTauthority file when the user logged in to CDE. If, for some reason, the $HOME/.TTauthority file becomes corrupted, clients are not able to send a valid key to the ttsession message server. As a result, CDE cannot function normally and might not start at all.

You can use the /usr/dt/bin/ttauth list command to examine the contents of your $HOME/.TTauthority file. A corrupted file might contain null values that might cause the ttsession message server to dump core while trying to read the file. The $HOME/.dt/errorlog file contains the following error message if the ttsession message server could not start: 

dtsession: Unable to start message server - exiting.

If this problem occurs, remove the $HOME/.TTauthority file and restart CDE by becoming the root user and executing the /sbin/init.d/xlogin stop and then the /sbin/init.d/xlogin start commands.

When you log back in to CDE, a new $HOME/.TTauthority file is created that contains a valid key.

If the home directory is shared with other users, the other users must also restart CDE and log out and log in again.

7.4    Internationalization

The following notes apply to restrictions on use of internationalization features in the windowing environments.

7.4.1    Unicode Locales and Dense Code Locales

Prior to Tru64 UNIX Version 5.1B, dense code locales with a compact wide character encoding were the only fully supported locales. Starting with Version 5.1B, an equivalent set of Unicode locales (formerly known as the @ucs4 locales) are also shipped. These Unicode locales use Unicode (UTF-32) as their wide character encoding, thus enabling better interoperability with other operating systems, such as Windows, and interoperability with processes running in different locales.

The system administrator can choose to set either the Unicode locales or the dense code locales as the system default using the i18nconfig SysMan tool. See l10n_intro(5) for information on how to switch the set of system default locales.

However, applications that depend on dense code wide character encoding may have to be recompiled or modified to work with the new Unicode locales.

These changes are made to make this implementation better conform to the Unicode Standard.

7.4.2    Minor Behavioral Changes in Unicode Iconv Converters

Prior to Tru64 UNIX Version 5.1B, converting a coded character set to Unicode (UTF-16 or UTF-32) without generating a Byte Order Mark (BOM) at the beginning of the output stream writes the Unicode data in little-endian format (least significant byte first). However, starting with Version 5.1B, the default behavior is to write out big-endian Unicode data values if BOM is suppressed. If BOM is allowed, little-endian data is written out as before. Applications that use the operating system's Unicode conversion capability without generating a BOM should be aware of this behavioral change.

Moreover, if the UTF-16BE, UTF-16LE, UTF-32BE, or UTF-32LE names are used as iconv converter output encoding, no BOM will be prefixed to the data stream by default. BOM was added before Version 5.1B.

The assumption that the byte value of a single-byte character set is equal to the wide character value is now no longer valid for the Unicode locales. Applications that make this assumption in their code, may not work properly with the single-byte Unicode locales.

7.4.3    Japanese Keyboard Support in Console Mode

When running in single-user or console mode, Tru64 UNIX now supports two new Japanese keyboard types (JIS and ANSI) on AlphaStation and AlphaServer systems. (Japanese keyboard support is not available on TURBOchannel-based machines.)

To use JIS-type Japanese keyboards, like the PCXAJ-AA and LK411-JJ, set the language console environment variable to 50, as follows: 

>>> set language 50

To use ANSI-type Japanese keyboards, like the LK411-AJ, set the language console environment variable to 52, as follows: 

>>> set language 52

7.4.4    Default Keyboard Setting Might Prevent User Login

When a user logs in to a system, the default keyboard setting must be appropriate for the keys that the user presses when entering characters in the user name and password fields. Otherwise, characters that are correct from the user perspective, given the keyboard being used, might be treated as invalid. In this case, the user cannot log in to the system. This situation most often arises when a keyboard is being used in one language and the default keyboard setting is another language. You can change the default keyboard setting at the console prompt or, if the required language is not available at the console level, by editing the Xserver.conf file to change the keymap used by the X server. See keyboard(5) for more detailed information about changing keyboard settings.